The goal of this clinical trial is to compare patient-reported and performance-based outcomes of patients followed with a standard exercise program based on telerehabilitation and patients followed with action observation therapy program added to a standard exercise program based on telerehabilitation after total knee arthroplasty surgery.

The main questions it aims to answer are:

• [What is the effect of action observation therapy added to a telerehabilitation-based standard exercise program on patient-reported outcomes after total knee arthroplasty surgery?]
• [What is the effect of action observation therapy added to a telerehabilitation-based standardized exercise program on performance-based outcomes after total knee arthroplasty surgery?]

Participants will be divided into three groups by computer-assisted randomization method: Group 1: home exercise with information leaflet group, Group 2: information leaflet + telerehabilitation-based standard exercise program group, Group 3: information leaflet + telerehabilitation-based standard exercise program + action observation therapy group.

Patients in the second and third groups will be followed up with the telerehabilitation method accompanied by a physiotherapist for 30 minutes 3 days a week for 6 weeks after discharge. The third group will receive a standard exercise program 3 days a week and 15 minutes of action observation therapy via video conferencing.

The goal of this clinical trial is to compare patient-reported and performance-based outcomes of patients followed with a standard exercise program based on telerehabilitation and patients followed with action observation therapy program added to a standard exercise program based on telerehabilitation after total knee arthroplasty surgery.

The secondary aim is to investigate the effect of a telerehabilitation-based standard exercise program added to the home program (information leaflet) on patient-reported and performance-based outcomes.

The surgical operations of all patients participating in the study will be performed by the same surgical team and a standard physiotherapy program will be applied to all patients until discharge.

Participants will be divided into three groups by computer-assisted randomization method: Group 1: home exercise with information leaflet group, Group 2: information leaflet + telerehabilitation-based standard exercise program group, Group 3: information leaflet + telerehabilitation-based standard exercise program + action observation therapy group.

Patients in the second and third groups will be followed up with the telerehabilitation method accompanied by a physiotherapist for 30 minutes 3 days a week for 6 weeks after discharge. The third group will receive a standard exercise program 3 days a week and 15 minutes of action observation therapy via video conferencing.

Telerehabilitation sessions will include information about the process and exercise training. Action observation therapy will include showing videos of the exercises in the exercise program. All patients will be evaluated before surgery and at the third, sixth, and twelfth weeks after discharge.

Evaluations

Descriptive Data: Descriptive data of the patients will be recorded using an evaluation form.

Patient Reported Assessments:

• Western Ontario McMaster University Osteoarthritis Index (WOMAC): This index questions clinically significant problems in the areas of pain, stiffness and physical function in patients with osteoarthritis of the hip and knee.
• Pain intensity: Pain intensity will be assessed with the Visual Analog Scale (VAS).
• Knee range of motion: Active and passive knee range of motion will be measured in the sitting position with a digital goniometer (HALO Medical Devices, Australia)
• Quality of Life Assessment: Knee Injury and Osteoarthritis Outcome Score - Activities of Daily Livings Scale (KOOS-ADLS) and EuroQol Group (EQ-5D) scales will be used for quality of life assessment.KOOS-ADLS is a scale used to detect symptoms and limitations in daily life tasks.The EQ-5D index scale consists of a questionnaire with five dimensions (movement, self-care, usual activities, pain/discomfort and anxiety/depression).
• Physical activity assessment: International Physical Activity Survey (IPAQ-Short Form) and smart phone pedometer application (Samsung Health®) will be used for physical activity assessment. The IPAQ-Short Form consists of 7 questions asking about various degrees of physical activity and sedentary behaviors in the past 1 week.
• Patient Satisfaction Assessments: Patient satisfaction with telerehabilitation sessions will be assessed. Technical quality (such as reliability of technology, quality of audio/video synchronization, quality of image, quality of sound), achievement of treatment goals of the session and overall satisfaction with the session will be questioned.

Performance Based Assessments:

The tests recommended by the research groups of 30 seconds of sit and stand, 40 meters fast walking and stair climbing will be used.

• Lower extremity muscle strength: Lower extremity muscle strength will be assessed by 30 seconds sit and stand test.
• Walking speed: In the 40-meter walk test, the patient is asked to walk a distance of 40 meters as fast as possible and the time in seconds is recorded.
• Locomotor performance: Locomotor performance will be assessed with the stair climbing test. The patient will be asked to ascend and descend 9 steps 16-20 centimeters long stairs as quickly but safely as possible.

Inclusion Criteria:

• Volunteer
• 40 years and older
• Undergo primary unilateral total knee arthroplasty surgery after the diagnosis of osteoarthritis
• Can understand, speak and write Turkish
• Understand verbal and written information given
• Internet access
• Able to use video conferencing program

Exclusion Criteria:

• Revision total knee arthroplasty surgery
• Previous major surgery on the extremity to be operated on
• Additional comorbid diseases such as rheumatoid arthritis, cancer
• Has any engine defect that may affect performance
• With a diagnosed psychiatric disorder
• People with alcohol or drug addiction
• Hearing or visual impairment that cannot be corrected with hearing aids or glasses
• Morbidly obese (BMI > 40 kg/m2)
• Who will not be able to participate in a six-week rehabilitation program

Exclusion Criteria for Volunteers:

• Patients who did not come to follow-up after surgery for any reason,
• Patients who want to leave the study,
• Patients who are unable to continue the study due to an additional condition will be excluded from the study.

Double-blind